Electric fuse switch construction



p 8, 1953 s. 1. LINDELL 2,651,694

I ELECTRIC FUSE WITCI-I CONSTRUCTION Filed April 26. 1950 4 Sheets-Sheet1 IN VEN TOR.

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Sept. 8, 1953 s. I. LINDELL 2,651,694 ELECTRIC FUSE SWITCH CONSTRUCTIONFiled April 26, 1950 4 SheetsSheet 4 HVVENTDR.

Patented Sept. 8, 1953 ELECTRIC FUSE SWITCH"CONSTRUCTION Sigurd I.Lindell, Chicago, Ill., assignor to S & 0. Electric Company, Chicago,111., a corporation of Delaware Application April-26, 1950, Serial No.158,264-

17 Claims. 1

Thisinventionrelates. generally, to automatically disconnecting highvoltage high interrupting; capacity electric fusev switches and it hasparticular. relation to such devices having relatively great size.andweight arranged for mounting, on an insulator bushing whose strengthis relatively slight, .such as the bushing of a transformer containing ahigh voltage terminal, although its application isnot so limited.

Among the objects ofthis invention are: To flexibly and pivotally mounton-the high voltage terminal insulator. bushing of a transformer anautomatically disconnecting high voltage high interrupting capacity.fuse; to arrange the fuse so as to be spring biased from a generallyhori-- zontal c-losedposition to a generally vertical open position; tolimit the; impact incident to arrestin the fuse in the open position toa practically attainable minimum; toaccomplish this in part byarresting; it in a substantially vertical position; to bias the fuse asaforesaid by a-spring having a non-linear torque characteristicgenerally corresponding to the torque characteristic of gravity actin onthe fuse to bias it toward the closed-positionasit moves therefrom tothe open position; to construct the biasing mechanism so that it iscapable of breaking loose from.

ice that. might Otherwise interfere-with or prevent opening of the fuseswitch; to apply the principal biasing torque. for opening the fuseswitch at its pivot end by a main spring; to

pretension the main spring; to provide a biasing action at the other endof the fuse switch by an auxiliary or; kicker spring to assist mini.-tiating its opening movement and in overcoming. the force of gravity; topivotally mount the fuseswitch on a hinge member and provide interengageable shoulders thereon for, limiting theopening movement of theformer; to resiliently mount the hinge member on the end of the bushing;to interpose a resilient stop between the fuse andthe hinge member; tolatch the fuse. switchin the closed position by latchmeans' on. the endopposite the pivot end; and-to. elevate.

the latch end-slightly above thepivot end.

Other objects of this-invention will, in part;

b obvious and-in part appear hereinafter.

This invention isdisclosed in the embodiment. thereof: shown intheaccompanying drawings: and itcomprisesithe features of constructiom.combinationof elements; and arrangement of parts, which willbeexemplified in the constructionjhereinaftenset forth and thescopeof theapplication ofwhich. will beindicatedin theappended claims.

arrester, and both arranged to carry at their upper ends a fuseswitch;

Figure 2 is a view, similar to Figure 1, illustrating only the upperendsof the insulator bushing and insulator support and showing how a fusewhich forms a part of the fuse switch is mounted thereon, the fuseswitch being shown closed;

Figure 3 is a view similar to Figure 2 but showthe fuse in the positionwhich it occupies immediately after it is unlatched from the closedposition andv starts to swing to the open position;

Figure 4 is aview, in side elevation, of the fuse in the position towhich it is swung in the opening movement, the position here shown beingatv the extreme limit of travel permitted in the openingdirection, about20 past the vertical position;

Figure-51s aview, similarto Figure. 4, showing thefuse inthe openposition and at rest after recoil;

Figure 6 is. a perspective view of the fuse switch construction inwhichthe present invention is.

so that the fuse in its closed position lies in a.

generally horizontal position;

Figure Tie a view in side elevation, at an enlargedi scale, showing inmore detail the construction. of the latch terminal, certain partsbeingbroken away; and

Figure 8'is aview, at an enlarged scale, showing. the .detailsof.construction of the hinge. terminal and operating assembly, certainparts being broken away.

Referring now particularly to Figure 1 of the drawings, it. will beobserved that the reference character. llll designatesv a portion of atrans.- former tank from which a vertical insulator bushing or. supportmember I l-extends upwardly. Within theinsulator bushing H thereisprovided ahighvoltage terminal l2 which may be in the form-cfaroclorin the form: of anexible 0011-. ducton. for connection tooneorthe high voltage terminals Ofthe-tTanSfOrmeras will be understood.

It extends into-the transformer tank Hi.

actress readily. The terminal 12 extends through the upper end of thebushing it and is threaded for receiving a nut l3 which serves, in part,to clamp a hinge terminal and operating assembly, shown generally at it,in place on the upper end of the threaded bushing ii.

In Figure 2 a fuse is illustrated, generally, at it that is arranged tobe pivotally mounted on the hinge terminal and operating assembly It. Atits other end the fuse i5 is carried by a latch terminal and auxiliaryoperating assembly that is indicated, generally, at it; A tubularconductor I? is provided for carrying the latch terminal and auxiliaryoperating assembly 16 at its upper end. At its lower end the tubularconductor if is carried by a vertical porcelain insulator or supportmember it which, as illustrated, is spaced horizontally from the bushingii. The tubular conductor it is employed to elevate the end of the fusel5 carried thereby slightly with respect to the other end so that itwill be more weatherproof. Generally, however, the fuse i5 is mounted inwhat is considered to be a horizontal position although, as illustratedin Figure 2 and described above, the fuse l5 in the closed position isinclined slightly to the horizontal.

Any suitable means such as a mounting frame is may be employed forsupporting the lower end of the vertical insulator is. A terminal pad 28is located at the lower end of the tubular conductor it to permitconnection of a line conductor thereto.

The fuse it: together with the hinged terminal and operating assembly l6and the latch terminal and auxiliary operating assembly it togetherconstitute a fuse switch which, as shown in Figure 1, is arranged toclose and open the circuit to one terminal of the high voltage windingof a transformer. The details of construction of the fuse l5 form nopart of the present invention. For illustrative purposes the fuseconstruction disclosed in application Serial No. ($63,83 filed April 22,1946, now U. S. Patent No. 2,599,186, dated June 3, 1952, and assignedto the assignee of this application may be used. However, it will beunderstood that other fuse constructions can be employed if desired. Anysuitable contact construction can be used. For example, the contactconstruction disclosed in application Serial No. 57,346, filed October29, 1948, now U. S. Patent No. 2,578,255, dated December 11, 1951, andassigned to the assignee of this application may be used. It will beunderstood also that other types of contact construction can be employedas may be desired.

The fuse it includes a fuse tube 23 of insulating material having aterminal 22- at its lower end which is provided with trunnions 25 thatare arranged to interfit with the lower end portion 26, Figure 8, oflongitudinally extending slots 2? in upwardly extending arms 28 of agenerally U shaped hinge member, shown generally at 23. The hinge member29 is formed preferably of good electrical conducting material such asred brass. Its lower central portion 80 is secured by bolts iii to anupper arm 32 of a generally U- shaped resilient mounting adapter that isindicated, generally, at 31-3. Preferably the mounting adapter 33 isformed of a resilient conducting material such as Phosphor bronze orhard drawn copper. Its lower arm 23d may be secured by bolts 35 to theupper end of the insulator bushing ll where a metallic cap H is providedfor this purpose. In addition, as shown in Figure l, the nut is on thethreaded upper end of the 4 terminal l2 also serves to hold the lowerarm 34 in position on the cap ll.

Where the insulator bushing H is merely another insulator, such as shownin Figure 6, the high voltage terminal l2 would be omitted. In such casethe lower arm 3 1 may have an extension in the form of a terminal pad 36to permit connection of another conductor thereto The provision andresilient construction of the mounting adapter 33 are important. It willbe noted that the upper and lower arms 32 and 34 extend generallyhorizontally with the intermediate portion providing a flexible sectiontherebetween. This flexible construction cushion to a considerableextent the shock that is incident to the stopping of the fuse i5 in theopen position as shown in Figure Insulator bushing ll of the type shownin Figure l have different allowable cantilever loads which they arecapable of withstanding. lhese are in the neighborhood of '75 to 100pounds. For a fuse 55 designed for use in a circuit energized at avoltage of 69,000 volts the fuse l5 may weigh from 18 to 20 pounds withthe terminals and fittings mounted thereon. This weight may be increasedas much as 25 per cent where the fuse is coated with ice. Whileprovision must be made for swinging the fuse 15 from the position shownin Figure 2 to the position shown in Figure 4, so that it will beoperated alone or in the iced condition, it will be appreciated that aconsiderable amount of kinetic energy must be dissipated when the fuseis stopped in the generally vertical position. By employing theresilient mounting adapter 33, some of this energy is absorbed infurther flexing it and thus the force to which the upper end of theinsulator bushing H is subjected is reduced to within allowable limits.

Another factor that must be taken into consideration in swinging a fusefrom the enerally horizontal position shown in Figure 2 to the generallyvertical position shown in Figure 4 is the change in torque appliedthereto by gravity which varies as the fuse it; approaches the verticalposition. Specifically the torque applied by gravity varies as thecosine of the angle between the fuse l5 and the horizontal from amaximum at zero degrees to a minimum at In order to avoid overshootingof the fuse l5 much beyond the vertical position, it is desirable thatthe biasing means which swings it to this position have a non-linearcharacteristic which approaches that applied by gravity to the fuse E5in opposing its movement from the horizontal to the vertical position.

In accordance with this invention a non-linear U-shaped main spring 40is employed for this purpose. It may be formed of Phosphor bronze wireand for use with fuses 15 having a rating of 69,000 volts it may have adiameter of 5's inch. Apertured bosses M, Figure 8, are provided onopposite sides of the hinge member 29 for receiving the free straightend portions 42 of the main spring i6. These end portions 42 may besecured in the bosses il by suitable pins 43. As shown more clearly inFigure 8 of the drawings, the main spring 40 is curved outwardly andupwardly on the side of the hinge member 2t away from the insulator orsupport member It. In order to provide the non-linear characteristic,the general center of curvature of the spring 40 is offset from the axisof rotation of the fuse l5 through the trunnions 25. Further,intermediate portions of the arms of the U-shaped main spring ii! arecurved on different radii. For example in asst-pea'the-spring'construction referred to above the portion indicated at '44may have'a radius of 6% inches when the main spring 40 is completelyunstressed. The portions -45, 46 and 4'! have radii respectively asfollows: 75% inches, 5%, and 4%,;- inches. The joined end portions 48 ofthe U -shaped main spring 40 are interconnected by a central portion 49which extends underneath stop shoulders 50 that are formed integrallywith the upwardly extending arms '28 of the hinge member 29 on the sidetoward the vertical insulator "or support member Hi. In the position ofthe main spring '40, as shown in Figure 8, where the central portion 49is in engagement with the stop shoulders 50, the spring 40 is in aprestressed condition. That is, if the stop shoulders '50 were removed,the central portion 49 would occupy a position substantially higher andto the right of the position shown in Figure 8. By prestressing the mainspring 46 it is possible to employ it in a region where the torqueexerted thereby is at a maximum for initiating the movement of the fuse'15 from the generally horizontal position while requiring a minimum ofmovement of the central (portion 49 and flexing of the main spring 40 tostore energy for effecting this operation.

By providing the main spring 40 with a relatively large free length, thebreaking loose under icing conditions is facilitated. When ice collectson the arms of the main spring 49, as soon as it begins, to hex forswinging the fuse to the open position, the ice thereo'n is cracked andfalls away. Thus there is substantially no interference in the operationof the fuse 15 under icing conditions when the main spring 58 of thecharacter and construction described herein is employed. Abutments inthe form of bosses 5! are located on the outer sides of the upwardlyextending arms 28 and bear against the straight end portions 42 of themain spring ii? for holding them in position. The bosses 5| are formedintegrally with the hinge member 29.

As shown in Figure 4 an abutment 52 is formed on the terminal 24 and, asshown in Figure 2,

is arranged to engage the central portion 39 of the main spring 50. Itis through the abutment 52 that the main spring transmits its operatingtorque to the fuse :5. In the open position, as shown in Figure 5, theabutment 52 engages the central portion 49 which, in this position, isrestrained by the stop shoulders 50 in the prestressed condition of thespring 40. When the fuse l 5 is swung from the open position, shown inFigure 5, to the closed position, shown in Figure 2, the central portion49 of the spring 50 is picked up'b'ythe abutment 52 and is carrieddownwardly to further tension the main spring 48.

Adjacent the abutment 52 there is provided a convex contact engagingportion 53 on the terminal24 that is arranged to be engaged by a contactfinger 54 which is carried by the hinge member '29. The construction ofthese contact members is set forth in more detail in theapplication'referred to above.

As a further means of decreasing the-shock in- 'cident to the stoppingof the fuse l5 in the position shown in Figure 4, a rubber bumper 55,Figure 8, is provided on each of the upwardly extending arms 28 on theinner side thereof. Each rubber bumper '55 is held in position by a bolt'55. It will be understood that, when the fuse I5 is swung to theposition shown in Figure 4, it engages the bumpers 55 which act as shockabsorbers. Since they are carried by the rela- 6 'tively rigid and heavyhinge member 29 that iri turn is resiliently mounted on the resilientmounting adapter -33, the shock absorbing action of the mounting isfurther enhanced.

With a view to preventing the fuse [5 from being thrown out of the hingemember 29 when it is stopped in the position shown in Figure 4,shoulders 51, Figure 4, are provided on opposite sides of the terminal24 and they arearranged to engage shoulders 58, Figure 8, which extendinwardly from the upper ends of the arms 28 of the hinge member 28. Inthe position shown in Figure 4, the shoulders 51 are inengagement withthe shoulders 58 and the trunnions 25 have been moved out of the lowerend portions 26 of the slots 21'. However, the construction is such thatthe trunnions "25 bear against the left hand side of the slots 21, asviewed in the drawings, and they, together with the interengagingshoulders 57 and '58, prevent the fuse l5 from being thrown out of thehinge member 29. As described hereinbefore, the shock, incident to thestopping of the fuse l5 in the position shown in Figure 4 is absorbedpartly by the rubber bumpers 55, partly by the resilient mountingadapter 33 and the balance is absorbed by the insulator bushing II orits equivalent insulator, such as that shown in Figure 6.

Provision is made at the upper endof the fuse :5 for latching it to thelatch terminal and auxiliary operating assembly 16. For this purpose aterminal 88 is positioned at the upper end of the fuse tube 28.Extending from the terminal as shown in Figure 4, is a latch hook 5!which carries a roller 62 at its outer end. The roller 62 is arranged toengage behind a roller Figures 2 and '7, that is carried by a latchlever '64 which is pivoted at 65 on a base member 66. As shown in Figure7 the base member 65 is positioned on the upper end of the tubularconductor IT. A spring 67 cooperates with the latch lever 54 to bias theroller 63 so that it will engage the roller 62 and latch the fuse 23 inthe closed position shown in Figure 2.

In order to move the roller 63 out of lockin engagement with the roller62 a pry out lever 58 is pivoted on the latch lever "54 near its forwardend and it has nose portions "69 that are arranged to be engaged by aflange ill for lifting the pry out lever '68 and thereby the latch lever6 The flange T6 extends radially outwardly from a latch tube II that isslidably mounted on the upper end of the fuse 15. A described in moredetail in U. S. Patent No. 2,599,186, referred to above, provision ismade within the fuse i 5 for causing the latch tube II to move from theposition shown in Figure 2 to the position shown in Figure 3 on theoccurrence of a predetermined overload for swinging the pry out lever 68and the latch lever 64 to the unlatched position. This operation may beaccomplished manually by means of a fork 72 which is arranged to engagethe underside of the flange 1s. The fork l2 constitutes a part of a hookstick release member 13 that is pivoted at M on the terminal 60. Thehook stick release member l3 has an eye 15 for receiving the prong of ahook stick which permits the member 33 to beswung in a clockwisedirection, as viewed in Figure 2, to cause the ends of the fork 72 toengage 'the underside of the flange T0 and move the latch tube ll to theunlatching position.

Any suitable means can be employed for making good electrical contactbetween the base member 65 and the terminal-65. For this pur pose aU-shaped contact member 18 may be employed having a U-shaped reinforcingspring 79 as described in U. S. Patent No. 2,578,255, referred toherelnbefore. The U-shaped contact member 78 and correspondingly shapedreinforcing spring 19 may be secured to the upper side of the basemember 66 by bolts 80, Figure 7. In addition a stop pin 8! is employedfor determining the closed position of the fuse 15.

While the main spring 46 may be provided and arranged so that, when thefuse i is unlatched from the latch terminal and auxiliary operatingassembly Is, it can by itself swing the fuse [5 to the open positionshown in Figure 4, it is preferable to provide additional mechanism forassisting it in initiating the movement of the fuse IE to the openposition. Such assistance may be required when the mechanism is coveredwith ice and must be broken loose. For this purpose a generally U-shapedauxiliary or kicker spring, shown generally at 8'1, Figure 2, can beused. The free ends 85 of the spring 86 are secured by bolts 83 to theupper side of the base member 56. The intermediate portions 81, Figure7, of the arms forming the spring 8 2 are curved outwardly and upwardlyon the side of the latch terminal and auxiliary operating assembly H5away from the insulator bushing l5. These intermediate portions 8'5 havestraight portions 88 extending therefrom which terminate in end portions89 that are joined by a central curved portion 90. As shown more clearlyin Figure 6, the central curved portion Q8 bears against the undersideof the fuse tube 23 adjacent the terminal 60. When the fuse i5 isclosed, as shown in Figure 2, the straight portions 88 of the spring 8are inclined downwardly toward the free ends 85. In the open position ofthe fuse E5, the straight portions 38 are generally parallel to the freeends 85 as shown in Figure '7. For illustrative purposes it is pointedout that the auxiliary or kicker spring 841 may be formed of Number fPhosphor bronze wire. The intermediate portion 8? in the unstressedcondition may have a radius of i inches. The straight portions 88 areabout 4% inches long. The inclined end portions 85 are about 2% incheslong. The arms of the U-shaped auxiliary or kicker spring 84 may bespaced about 4 inches apart.

In Figure 6 of the drawings, the alternate construction referred tohereinbefore is illustrated. A second insulator 93 is employed which maybe a duplicate of the vertical insulator i8. As shown the insulators l8and 93 may be mounted on a channel base 94. Of course, it is possible tohave the insulator ii in Figure 6 longer than the insulator 93 and tothen dispense with the tubular conductor ll which is employed to 10-cats the fuse in the inclined position. However, since the insulator 93must be long enough to withstand the rated line voltage, the addi tionalinsulation provided by the longer insulator I8 is unnecessary and ismore expensive than it is to provide the tubular conductor l'l.

Since certain further changes can be made in the foregoing constructionand different embodiments of the invention can be made without departingfrom the spirit and scope thereof, it is intended that all matter shownin the accompanying drawings and described hereinbefore shall beconsidered as illustrative and not in a limiting sense.

What is claimed as new is:

1. A fuse arranged to be moved automatically from a generally horizontalclosed position to a generally vertical open position, comprising, incombination, horizontally spaced insulating support members, a fusepivotally mounted on one support member to swing upwardly and latched tothe other support member, and spring means reacting between said onesupport member and said fuse to swing it upwardly on unlatching of thesame from said other support member, said spring means beingcharacterized by applying to said fuse a diminishing torquecorresponding generally to and opposing the torque applied to said fuseby gravity and acting principally in a vertical direction on said fuseto swing it from closed to open position whereby the torque exerted bysaid spring means in opening said fuse decreases generally in the sameproportion that the torque exerted by gravity biasing said fuse closeddecreases.

2. A fuse arranged to be moved automatically from a generally horizontalclosed position to a generally vertical open position comprising, incombination, horizontally spaced insulating support members, a fusepivotally mounted on one support member to swing upwardly and latched tothe other support member, generally C-shaped spring means reactingbetween said one support member and said fuse to swing it upwardly onunlatching of the same from said other support member, the effectivecenter of curvature of said c-shaped spring means being offset from thepivot axis of said fuse so that the torque applied thereby to said fusecorresponds generally to and opposes the torque applied to said fuse bygravity and acts principally in a vertical direction on said fuse toswing it from closed to open position whereby the torque exerted by saidO- shaped spring means in opening said fuse decreases generally in thesame proportion that the torque exerted by gravity biasing said fuseclosed decreases, and additional spring means reacting between saidother support member and said fuse and acting to swing the same upwardlyon unlatching thereof to provide a thrust thereon in addition to thatapplied by said C-shaped spring means for breaking said fuse loose underall operating conditions.

3. A fuse arranged to be moved automatically from a generally horizontalclosed position to a generally vertical open position comprising, incombination, horizontally spaced insulating support members, a fusepivotally mounted on one support member to swing upwardly and latched tothe other support member, spring means reacting between said one supportmember and said fuse to swing it upwardly on unlatching of the same fromsaid other support member, said spring means being characterized byhaving more energy stored therein than is necessary to swing said fusepast its vertical position, and stop means cooperating with said springmeans to limit the movement thereof and cause the same to disengage saidfuse in advance of its reaching the vertical position thereof and beforesaid energy stored in said spring means has been released completelywhereby said fuse thereafter continues to swing substantially only underthe influence of the momentum previously acquired from said springmeans.

4. A fuse arranged to be moved automatically from a generally horizontalclosed position to a generally vertical open position comprising, incombination, horizontally spaced insulating support members, a fusepivotally mounted on one support member to swing upwardly and latched tothe other support member, spring means re- 9 acting between saidone'support memberand said fuse to swing it upwardly on unlatching ofthe same from said other support member, said spring means beingcharacterized by having more energy stored therein than is necessary toswing said fuse past itsvertical position, stop means cooperating withsaid spring means tolimit the movement thereof and cause the same todisengage said fuse in advance of its reaching the vertical positionthereof and before said energy stored in said spring means has beenreleased completely whereby said fuse thereafter continues to swingsubstantially only under the influence of the momentum previouslyacquired from said spring means, and additional spring means reactingbetween said other-support member and said fuse and acting to swing thesame upwardly on unlatching thereof to provide a thrust thereon inaddition to that applied by the first mentioned spring means forbreaking said fuse loose under all operating conditions likely to beencountered.

5. A fuse arranged to be moved automatically from a generally horizontalclosed position to a generally vertical open position comprising incombination, horizontally spaced insulating support members, a generallyU-shaped resilient mounting adapter with the arms thereof extendinggenerally horizontally one above the other and one arm secured to one ofsaid support members, a fuse pivotally mounted on the other arm of saidmounting adapter to swing upwardly and latched to the other supportmember, and spring means reacting between said other arm of said adapterand said fuse to swing; it upwardly on unlatching of the same from saidother support member.

6. A fuse switch comprising, in combination, a pair of horizontallyspaced insulating support members, a hinge member carried by one of saidsupport members, a generally U-shaped main spring with the free endsofits arms secured to opposite sides of said hinge member andthe-intermediate portions of its arms being curved outwardly andupwardly on the side of said hinge member away from said other supportmember and toward the same with the joined end portions extendingdownwardly; a fuse including.- a fuse tube having terminals at its ends,one of said terminals being pivotally mounted on said hinge member andbeing arranged andadapted to cooperate with said joined ends of saidmain spring to tension the same when said fuse is swung to its generallyhorizontal closed position and whereby said fuse is biased by said mainspring to a generally vertical open position, and

the other terminal on said fuse tube having latch means and latchreleasing means;. and terminal means carried by said other supportmember including latch means for cooperating. with said latch means onsaid other fuse tube terminal to hold said fuse in closed position.

'7. A fuse switch comprising, in combination, a pair of horizontallyspaced insulating. support members, a generally U-shaped hinge memberhaving its lower central portion secured to one of said support members,stop means on the upwardly extending arms of said' U-shaped hinge memberon the side thereof facing the other support member, a. generallyU-shaped main spring with the free ends of its arms secured to oppositesides of said hinge member adjacent its central portion and theintermediate portions of its arms being curved outwardly and upwardly onthe side of said arms'of said. hinge member away from said other supportmember and to- Ward the same with the joined end portionsextendingdownwardly and underneath said stop means and adapted to berestrained thereby with said main spring in prestressed condition; afuse including a fuse tube having terminals at its ends, one of saidterminals being pivotally mounted on said arms of said hinge member andbeing arranged and adapted to cooperate with said joined ends of saidmain spring to further tension the same when said fuse is swung to itsgenerally horizontal closed position and whereby said fuse is biased bysaid main spring to a generally vertical open position, and the otherterminal on said fuse tube having latch means and latch releasing means;and terminal' means carried by said other support member including latchmeans for cooperating with said latch means on said other fuse tubeterminal to hold said fuse in closed position.

8. A fuse switch comprising, in combination, a pair of horizontallyspaced insulating support members, a generally U-shaped hinge memberhaving longitudinally slotted upwardly extending arms with shouldersextending inwardly at their upper ends and its lower central portionsecured to one of said support members, stop means on said upwardlyextending arms on the side thereof facing the other support member, agenerally U-shaped main spring with the free ends of its arms secured toopposite sides of said hinge member adjacent its central portion and:the intermediate portions of its arms being curved outwardly andupwardly onthe side'ofsaid arms of said hinge member away from saidother support member and toward the same with the joined end portionsextending downwardly and underneath said stop means and adapted to berestrained thereby with said main spring in prestressed condition; aremovable fuse including a fuse tubehaving terminals at its ends, one ofsaid terminals having trunnions for interfitting with the slots in saidarms of said hinge member to removably hingedly mount said fuse andshoulders for engaging said shoulders on the upper ends of said arms ofsaid hinge member to limit the opening movement of said fuse, said oneterminal having an abutment for cooperating with said joined ends ofsaid main spring to further tension the same when said fuse is swung toits generally horizontal closed position and. whereby said fuse isbiased by said main spring to a generally vertical open position, andtheother terminal onsaid fuse tube having latch means and latchreleasing means; and terminal means carried by said other support memberincluding, latch means for cooperating with said latch means on saidother fuse tube terminal to hold said fuse in closed position.

9. A fuse switch comprising, in combination, a pair of horizontallyspaced insulating support members, a generally U-shaped resilientmounting adapter with the arms thereof extending generally horizontallyone above the other and one arm secured to one of said support members,a generally U-shaped hinge member having its lower central portionsecured to the other arm of said mounting adapter, stop means on theupwardly extending arms of said U-shaped hinge member on the sidethereof facing the other support member, a generally U-shaped mainspring with the free ends of its arms secured to opposite sides of saidhinge member adjacent its central portion and the intermediate portionsof its arms being curved outwardly and upwardly on the side of said armsof said hinge member away from said other support member and toward thesame with the joined end portions extending downwardly and underneathsaid stop means and adapted to be restrained thereby with said mainspring in prestressed condition; a fuse including a fuse tube havingterminals at its ends, one of said terminals being pivotally mounted onsaid arms of said hinge member and being arranged and adapted tocooperate with said joined ends of said main spring to further tensionthe same when said fuse is swung to its generally horizontal closedposition and whereby said fuse is biased by said main spring to agenerally vertical open position, and the other terminal on said fusetube having latch means and latch releasing means; and terminal meanscarried by said other support member including latch means forcooperating with said latch means on said other fuse tube terminal tohold said fuse in closed position.

10. A fuse switch comprising, in combination, a pair of horizontallyspaced insulating support members, a generally U-shaped resilientmounting adapter with the arms thereof extending generally horizontallyone above the other and one arm secured to one of said support men bers,a generally U-shaped hinge member having longitudinally slotted upwardlyextending arms with shoulders extending inwardly at their upper ends andits lower central portion secured to the other arm of said mountingadapter, a generally U-shaped main spring with the free ends of its armssecured to opposite sides of said hinge member adjacent its centralportion and the intermediate portions of its arms being curved outwardlyand upwardly on the side of said arms of said hinge member away fromsaid other support member and toward the same with the joined endportions extending downwardly; a removable fuse including a fuse tubehaving terminals at its ends, one of said terminals having trunnions forinterfitting with the slots in said arms of said hinge member toremovably hingedly mount said fuse and shoulders for engaging saidshoulders on the upper ends of said arms of said hinge member to limitthe opening movement of said fuse, said one terminal having an abutmentfor cooperating with said joined ends of said main spring to tension thesame when said fuse is swung to its generally horizontal closed positionand whereby said fuse is biased by said main spring to a generallyvertical open position, and the other terminal on said fuse tube havinglatch means and latch releasing means; and terminal means carried bysaid other support member including latch means for cooperating withsaid latch means on said other fuse tube terminal to hold said fuse inclosed position.

11. A fuse switch comprising, in combination, a pair of horizontallyspaced insulating support members, a generally U-shaped resilientmounting adapter with the arms thereof extending generally horizontallyone above the other and one arm secured to one of said support members,a generally U-shaped hinge member having longitudinally slotted upwardlyextending arms and its lower central portion secured to the other arm ofsaid mounting adapter, stop means on said upwardly extending arms on theside there of facing the other support member, a generally U-shaped mainspring with the free ends of its arms secured to opposite sides of saidhinge member adjacent its central portion and the intermediate portionsof its arms being curved outwardly and upwardly on the side of said armsof said hinge member away from said other support member and toward thesame with the joined end portions extending downwardly and underneathsaid stop means and adapted to be restrained thereby with said mainspring in prestressed condition; a removable fuse including a fuse tubehaving terminals at its ends, one of said terminals having trunnions forinterfitting with the slots in said arms of said hinge member toremovably hingedly mount said fuse and having an abutment forcooperating with said joined ends of said main spring to further tensionthe same when said fuse is swung to its generally horizontal closedposition and whereby said fuse is biased by said main spring to agenerally vertical open position, and the other terminal on said fusetube having latch means and latch releasing means; and terminal meanscarried by said other support member including latch means forcooperating with said latch means on said other fuse tube terminal tohold said fuse in closed position, and a generally U-shaped auxiliaryspring with the free ends of its arms secured to opposite sides of saidterminal means, the intermediate portions of its arms being curvedoutwardly and upwardly on the side of said terminal means away from saidone support member and toward the same with the joined end portionsextending upwardly underneath said fuse tube adjacent said otherterminal and engaging said fuse for biasing the same upwardly.

12. A fuse switch comprising, in combination, a pair of horizontallyspaced insulating support members, a generally U-shaped resilientmounting adapter with the arms thereof extending generally horizontallyone above the other and one arm secured to one of said support members,a generally U-shaped hinge member having longitudinally slotted upwardlyextending arms with shoulders extending inwardly at their upper ends andits lower central portion secured to the other arm of said mountingadapter, stop means on said upwardly extending arms on the side thereoffacing the other support member, a generally U-shaped main spring withthe free ends of its arms secured to opposite sides of said hinge memberadjacent its central portion and the intermediate portions of its armsbeing curved outwardly and upwardly on the side of said arms of saidhinge member away from said other support member and toward the samewith the joined end portions extending downwardly and underneath saidstop means and adapted to be restrained thereby with said main spring inprestressed condition; a removable fuse including a fuse tube havingterminals at its ends, oneof said terminals having trunnions forinterfitting with the slots in said arms of said hinge member toremovably hingedly mount said fuse and shoulders for engaging saidshoulders on the upper ends of said arms of said hinge member to limitthe opening movement of said fuse, said one terminal having an abutmentfor cooperating with said joined ends of said main spring to furthertension the same when said fuse is swung to its closed position inclinedslightly to the horizontal and whereby said fuse is biased by said mainspring to a generally vertical open position, and the other terminal onsaid fuse tube having latch means and latch releasing means; andterminal means carried by said other sup port member including latchmeans for cooperating with said latch means on said other fuse tubeterminal to hold said fuse in closed position.

13. A fuse switch comprising, in combination, a pair of horizontallyspaced insulating support members, a generally U-shaped resilientmounting adapter with the arms thereof extending generally horizontallyone above the other and one arm secured to one of said support members,a generally U-shaped hinge member having longitudinally slotted upwardlyextending arms with shoulders extending inwardly at their upper ends andits lower central portion secured to the other arm of said mountingadapter, stop means on said upwardly extending arms on the side thereoffacing the other support member, a generally U-shaped main spring withthe free ends of its arms secured to opposite sides of said hinge memberadjacent its central portion and the intermediate portions of its armsbeing curved outwardly and upwardly on the side of said arms of saidhinge member away from said other support member and toward the samewith the joined end portions extending downwardly and underneath saidstop means and adapted to be restrained thereby with said main spring inprestressed condition; a removable fuse including a fuse tube havingterminals at its ends, one of said terminals having trunnions forinterfitting with the slots in said arms of said hinge member toremovably hingedly mount said fuse and shoulders for engaging saidshoulders on the upper ends of said arms of said hinge member to limitthe opening movement of said fuse, said one terminal having an abutmentfor cooperating with said joined ends of said main spring to furthertension the same when said fuse is swung to its closed position inclinedslightly to the horizontal and whereby said fuse is biased by said mainspring to a generally vertical open position, and the other terminal onsaid fuse tube having latch means and latch releasing means; andterminal means carried by said other support member including latchmeans for cooperating with said latch means on said other fuse tubeterminal to hold said fuse in closed position, and a generally U-shapedauxiliary spring with the free ends of its arms secured to oppositesides of said terminal means, the intermediate portions of its armsbeing curved outwardly and upwardly on the side of said terminal meansaway from said one support member and toward the same with the joinedend portions extending upwardly underneath said fuse tube adjacent saidother terminal and engaging said fuse for biasing the same upwardly.

14. A fuse arranged to be mounted on a post type insulator havinglimited cantilever load resisting characteristics comprising, incombina- I tion, a hinge member, a fuse pivoted to said hinge member toswing between closed and open positions, stop means for arresting saidfuse in the open position where it constitutes generally a prolongationof said insulator, and a generally U-shaped resilient mounting adapterwith the arms thereof extending generally normal to the longitudinalaxis of said insulator, one arm fast thereon and the other arm carryingsaid hinge member, said adapter being arranged to flex on 14 engagementof said fuse with said stop means whereby to dissipate a substantialportion of the energy applied thereto as a result of the momentum ofsaid fuse.

15. Means for rockably mounting a fuse on a support comprising, incombination, a relatively rigid and heavy hinge member for pivotallysupporting said fuse, a first resilient means mounting said hinge memberon said support, and a second resilient means supported wholly by saidhinge member and arranged to be engaged by said fuse when it swings toopen position to receive the kinetic energy thereof whereby saidrelatively rigid and heavy hinge member is disposed between said firstand second resilient means and acts mechanically in series therewith toreduce the shock imparted to said support.

16. Means for rockably mounting a fuse on a support comprising, insombination, a relatively rigid and heavy hinge member for pivotallysupporting said fuse, a generally U-shaped resilient mounting adapterhaving one arm carrying said hinge member and the other arm mounted onsaid support, and a rubber bumper on said hinge member arranged to beengaged by said fuse when it swings to open position, said resilientmounting adapter and said rubber bumper and said hinge member acting inseries to absorb the shock incident to arresting said fuse in the openposition.

17. A fuse arranged to be moved automatically from a generallyhorizontal closed position to a generally vertical open positioncomprising, in combination, horizontally spaced insulating supportmembers, a relatively rigid and heavy hinge member for mounting on oneof said support members, a fuse pivotally mounted on said hinge memberto swing upwardly and latched to the other support member, spring meansreacting between said hinge member and said fuse to swing it upwardly onunlatching of the same from said other support member, a resilientmounting adapter interposed between said hinge member and said one ofsaid support members and constituting the sole support of the former andacting as a shock absorber between said hinge and support member, andstop means on said hinge member cooperating with said spring means tocause the same to disengage said fuse in advance of its reaching itsvertical position.

SIGURD I. LINDELL.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,940,203 Bowie Dec. 19, 1933 1,965,391 Pittman et al. July 3,1934 2,074,913 Johnson Mar. 23, 1937 2,118,270 Schultz et al May 24,1938 2,166,782 Lemmon July 18, 1939 2,178,650 Schultz Nov. '7, 19392,230,955 Johnson Feb. 4, 1941 2,318,817 Triplett May 11, 1943 2,485,221Turnham et al Oct. 18, 1949

